Car Model Guide/ Issues/ Corrosion at the arches, sills and boot floor

Corrosion at the arches, sills and boot floor

Attaches to GH at chassis level · Body & corrosion · carried by 8 variants across 2 chassis

Overview

Corrosion at the arches, sills and boot floor is a common fault recorded against GH at chassis level, at any age. It shows up as bubbling paint along the rear arches and sills, and scaling or perforation in the boot floor and around the rear suspension mounts. Where it's documented, the repair runs €300–€2,000 (localised repair at the cheap end, panel and structural work at the dear end, costs dated 2026-07), and it can be checked before you buy. 8 variants across 2 chassis in this database inherit it.

€300 – €2,000

localised repair at the cheap end, panel and structural work at the dear end · costs dated 2026-07

Likelihoodcommon

Typical onsetany age

Detectableyes

Walk awayyes, without proof

Evidencedocumented

What happens

Symptom. Bubbling paint along the rear arches and sills, and scaling or perforation in the boot floor and around the rear suspension mounts.

Cause. This generation's corrosion protection doesn't match the reputation the make carries, and cars in salted climates suffer early. It's the fault that ends these cars, because the mechanicals usually outlast the body.

How to check it

Static checks

Put it on a ramp and look at the arches, the sills and the boot floor in good light before you look at anything else. Walk away from perforation rather than negotiating on it.

Engine off, ideally on a lift.

Body & corrosioncommonDetectable at viewingwalk away without proofevidence: documented

Every variant that carries this

Variant	Chassis	Body	Years	Risk	Good buy	Cost as % of good buy
2.0 MZR20	GH	hatchback	2007–2012	R2	€1,450	79%
2.0 MZR20	GH Estate	wagon	2007–2012	R2	€1,550	74%
2.5 MZR25	GH	hatchback	2007–2012	R2	€1,700	68%
2.5 MZR25	GH Estate	wagon	2007–2012	R2	€1,800	64%
2.0 MZR-CD RF7J	GH	hatchback	2007–2010	R5	€1,150	100%
2.0 MZR-CD RF7J	GH Estate	wagon	2007–2010	R5	€1,200	96%
2.2 MZR-CD R2AA	GH	hatchback	2009–2012	R4	€1,800	64%
2.2 MZR-CD R2AA	GH Estate	wagon	2009–2012	R4	€1,900	61%

The last column is the point. The same repair is an inconvenience on one variant and a reason to scrap the car on another. A failure costing a quarter of the vehicle's value changes the purchase decision regardless of how rare it is.